1. Field of the Invention
The present invention relates to a card edge connector which is inserted into a connector receiving chamber provided with a wiring substrate having a plurality of rectangular terminal connecting portions disposed in predetermined positions on both front and rear surfaces of the wiring substrate, and into which a plurality of terminals each having an elastic contact segment to be in contact with a terminal contact portion via the opening of a corresponding terminal receiving chamber are inserted.
2. Description of the Related Art
A card edge connector shown in FIG. 6 has been widely known. The card edge connector 1 of FIG. 6 includes terminals 5 each having elastic contact segment 4 inserted into terminal receiving chambers 3 and 3' on the upper side and the lower side of a rectangular connector housing 2. The card edge connector 1 is to be inserted into a connector receiving chamber 7 provided with a wiring substrate 6 in the middle.
In the middle of the connector housing 2, a space 8 for separating the terminal receiving chambers 3 and 3' and into which the wiring substrate 6 is inserted is provided. The terminal receiving chambers 3 and 3' are provided with openings 9 and 9' communicating with the space 8, respectively.
Each of the terminals 5 is made of a conductive metal material, and comprises an elastic contact segment 4 and a wire connecting portion 11 to which a wire 10 is connected by caulking. The elastic contact segment 4 is provided with a contact portion 12 protruding from the openings 9 and 9' by a predetermined length. The contact portion 12 is situated in the middle of the bent portion.
The connector receiving chamber 7 is formed by caving a device casing 13 so as to accommodate the connector housing 2. Both front and rear surfaces of the wiring substrate 6 are provided with a plurality of rectangular terminal connecting portions (not shown) sandwiched by the elastic contact segments and in contact with the contact portions one by one.
When the card edge connector 1 is inserted into the connector receiving chamber 7, each of the elastic contact segments 4 is brought into contact with corresponding one of the terminal connecting portions and bent by the front surface or the rear surface of the wiring substrate 6, so that electric connection can be obtained.
In the prior art, due to variations in lengths A, B, C, and D indicated in FIG. 6 (length A is the thickness of the wiring substrate 6, inclusive of the thickness of the terminal connecting portions; length B is the distance between two facing contact portions 12; length C is the distance between the inner walls of the connector receiving chamber 7; and length D is the height of the connector housing 2 in the direction corresponding to the length C), the contact load of the respective elastic contact segments against the respective terminal connecting portions cannot be stabilized, which might result in a fault in electric contact.
Since the device casing 13, the connector receiving chamber 7, and the connector housing 2 are all made of a synthetic resin material, they are liable to be adversely affected by a change in the environment. When they are used at a high temperature, the length C of the connector receiving chamber 7 and the length D of the connector housing 2 are increased, with the elastic contact segments 4 being in contact. As the increased amount becomes larger, the contact load becomes smaller.
Meanwhile, the elastic contact segments 4 are limited in terms of width, thickness, and flexibility, due to the limited spaces in the terminal receiving chamber 3 and 3' and the space 8. Moreover, only limited types of material can be used for the elastic contact segments 4, in view of conductive efficiency. As a result, it becomes difficult to absorb the contact load by adjusting the lengths, and a fault occurs in electric contact.